SIMFEROPOL, Ukraine (Reuters) - Armed men who took control of the airport in Ukraine's Crimean regional center of Simferopol on Friday are patrolling the airport grounds but have not moved into the passenger terminal and appear to be allowing the airport to function normally.

A Reuters eyewitness at the scene said the men, dressed in full battle gear and carrying assault rifles and machine guns, were moving freely in an out of the control tower.

A man called Vladimir, who said he was a volunteer helping the group, said: "I'm with the People's Militia of Crimea. We're simple people, volunteers ... We're here at the airport to maintain order. We'll meet the planes with a nice smile - the airport is working as normal."

He added that though he and other volunteers supported the actions of the armed men they did not know where the group was from.